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[in Japanese]
1994 Volume 23 Issue 1 Pages
1
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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T. KOSHIJI, Y. ODA, K. NISHIMURA, Y. OKAMOTO, T. BAN
1994 Volume 23 Issue 1 Pages
3-6
Published: February 15, 1994
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We designed a new method of pericardiomyoplasty using a rectus abdominis pedicled graft, to assist biventricular function. Eight mongrel dogs (weight 12-18 Kg, mean 14 Kg) were used in this study with and without production of heart failure. Unconditioned left rectus muscle (2.5g/Kg BW) were dissected as a pedicle with an intact internal thoracic artery and vein following a median sternotomy. Then the anterior half of the pericardium was replaced with a rectus abdominis pedicled graft. Three denervated intercostal nerves on the rectus muscle were simultaneously paced by 1:3 synchronous mode using burst stimulation (50Hz, 6v). Acute heart failure model in all dogs were produced by infusion of 2mg/Kg propranolol associated with volume loading. Stimulation by pericardiomyoplasty significantly increased in peak aortic pressure(AoP), peak right ventricular pressure (RVP), and descending aortic stroke flow (AoF) by 8.6%, 53.6%, and 18.1% respectively. After induction of acute heart failure AoP, RVP, and AoF were more pronouncedly augmented by this stimulation. This study suggests that the rectus abdominis is applicable for biventricular assistance despite small amount of muscle volume
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Y. EGOH, H. NAKAJIMA, S. KANEKO, H. ANDOH
1994 Volume 23 Issue 1 Pages
7-9
Published: February 15, 1994
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Computergraphical analysis for contraction and relaxation pattern of the latissimus dorsi muscle was performed in experimental study. Five mongrel dogs anesthetized for the preparation of left latissimus dorsi muscle. Pacing electrodes were installed into the muscle and stimulated by CMS (Telectronics) with 2.5V/0.25msec/60ppm. The ratio of muscle constriction was caluculated by measuring of area, and longitudinal and transectional lenghth in systolic and diastolic phase. In conclusion, proximal 1/3 of total muscle lenght showed good constriction, however, constriction of peripheral 1/3 was poor and significant diference was obtained between contraction of proximal and distal portion of the muscle.
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POWERED VENTRICLE (PRELIMINARY STUDY)
S. TAGUCHI, R. YOZU, H. ISEKI, H. SHIMIZU, R. TAKAHASHI, S. KAWADA
1994 Volume 23 Issue 1 Pages
10-13
Published: February 15, 1994
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The purpose of this study is to seek a new method of biventricular assistance using skeletal muscles. A single skeletal muscle-powered ventricle (SMPV) which counterpulsates systemic circulation, will be placed at the position beside the right ventricle. Since the SMPV dilates passively during the cardiac systolic phase, it is designed to press the right ventricle directly from outside and assist its contraction. This paper is a preliminary report and only the ability of the SMPV to assist the right ventricular contraction was assessed. In the cardiac systolic phase, the SMPV dilated passively with the pressure of 84mmHg and 0.8cm outwardly. From these results, it can be speculated that the SMPV which counterpulsates systemic circulation, has enough power to press and assist the right ventricle. Now the second phase of the study is ongoing with the SMPV placed at the position beside the right ventricle
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M. ENDO, H. NISHIDA, H. KOYANAGI, N. TUTUI
1994 Volume 23 Issue 1 Pages
14-17
Published: February 15, 1994
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As the cases for bleeding to occur in the large volume at insertion of IABP, we see that the gap between the thick sheath in about 10F and a slender guide wire in 0.035 inches left there is wide, causing bleeding while a balloon catheter is pushed forward along the guide wire. We have developed a new sheath with a grooved anti-bleeding plug preliminarily attached to the distal portion of the sheath. Bleeding is avoidable by inserting the anti-bleeding plug immediately into the gap between the sheath and the guide wire after pulling out the dilator. This plug i s removed without being hasty at the point of time when the balloon catheter advanced to the sheath along the guide wire, and the balloon catheter is inserted into the sheath. Result of experiment: To the volumes of bleeding when no plug was used being 600ml/min, the volumes of bleeding with the plug attached were small as 9-18ml/min(average11.5ml/min)
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—A CLINICAL STUDY—
H. SAIGENJI, H. TOYOHIRA, S. SHIMOKAWA, M. HASHIGUCHI, S. FUKUDA, H. M ...
1994 Volume 23 Issue 1 Pages
18-21
Published: February 15, 1994
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An eleven-year experience with intraaortic balloon pumping(IABP) in 57 patients with ischemic heart disease was analyzed with respects to early and late results. Three were 26 males and 31 females with a mean age of 66.8 years (range, 38 to 91 years). Coronary artery bypass grafting was performed in 39 patients, closure of ventricular septal perforation in 16, and other procedures in two. Sixty-one percents of patients(22/33) inserted preopera-tively could be weaned from IABP, 73% intraoperatively, and 89% postoperatively. The overall weaning rate from IABP was 68.4%(39/57). The main causes of hospital death were LOS in 17 patients, MOF in 6. Twenty nine patients (50.9%) were discharged from hospital. Twenty six patients are still alive, and 21 out of 26 patients show functional state in NYHA I. Actuarial survival rates at five years of overall and hospital survivors were 44.3%, 87.3%, respectively. We conclude that 1) LOS fellowed by MOF is the most prominent obstacle in IABP support, 2) operative survivors improve functional states, 3) alternative methods of circulatory support for the patients with uneffective IABP sunnort is recommended
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Hideki Y., Sunao W, Kazuhide H., Shunji U.
1994 Volume 23 Issue 1 Pages
22-24
Published: February 15, 1994
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which reduces the incidence of limb ischemia. To decrease the incidence of ischemia of the lower limb, we developed a new introducer sheath for IABP, which had 38 side holes (diameter: lmm). Patients were grouped into three. One-hundred seventy six patients who received IABP support with this fenestrated sheath (group B) were compared with 108 patients with the ordinary non-fenestrated sheath (group A) and with 30 patients with sheathless IABP (group C). There was no significant statistical difference among those three groups regarding age, sex, height, indications and the duration of IABP support. The frequency of ischanic episode of the lower limb was 5.7% (10/176) in the group B and 3.3% (1/30) in the group C. These figures were both significantly lower than that of group A (18/108; 16.7%) (p<0.005). From these data, we concluded that this fenestrated sheath and sheathless IABP allowed more blood flow to the lower limb and thus be effective to prevent limb ischemia, particularly in patients with a small caliber funeral artery. Thus far, we prefer using the fenestrated sheath because of the occasional difficulty in inserting the sheathless IABP. The former makes IABP cathter insertion more rapid, easier and safer, and also equally effective in preventing limb ischunia
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Y ABE, T CHINZEI, T ISOYAMA, K IMACHI, K IMANISHI, K MABUCHI, I FUJIMA ...
1994 Volume 23 Issue 1 Pages
25-29
Published: February 15, 1994
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Precessional displacement pump (PDP) is a small size continuous flow displacement-type blood pump with a new principle. A total artificial heart (TAH) was designed by using two PDPs and one motor. Under the design, two prototype models of PDP for the use as left side heart were constructed and their performance were examined. The priming volume and maximum continuous output of the two prototypes were 22ml, 20L/min. with 120mmHg of after load and 16ml, 19L/min. with 125mmHg of after load, respectively. The experimental model of pulsatile TAH was constructed by using two PDPs with 16ml of priming volume. The maximum pulsatile output was 7L/min. with 100mmHg of mean after load. These data demonstrated that a pulsatile TAH could be realized by using PDPs
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Ichiro SAKUMA, Hiroyuki TADOKORO, Yasuhiro FUKUI, Yasuhisa OHARA, Sets ...
1994 Volume 23 Issue 1 Pages
30-34
Published: February 15, 1994
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In order to design a centrifugal blood pump with less hemolytic and antithrombogenic properties, secondary flow inside the pump, such as vortex and recirculation, must be properly controlled. The flow visualization was conducted to investigate flow patterns in centrifugal blood pump. The visualization methods used were an oil film method and a tracer method. In the tracer method, movement of tracers were recorded by a high speed video camera which can take 3000 frames per second. The correlation between the visualized flow patterns and results of in vitro hemolysis tests was also investigated. Inadequate vane angles caused separations of streamlines, vortex formation, and sudden change in flow direction. Hemolysis increased under existence of such irregular flow patterns. Flow visualization experiments demonstrated that secondary washout vanes attached on the back side of the impeller can generate flow going from the center to the outer portion of impeller's backside and another flow in opposite direction at the same time. It may enhance washout effect at the backside of the impeller leading to less thrombogenic property
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—THEORETICAL ANALYSIS AND BASIC STUDY USING LARGE SCALE MODELS—
N. KABEI, Y. SAKURAI, K. TSUTIYA
1994 Volume 23 Issue 1 Pages
35-40
Published: February 15, 1994
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Recently Yano proposed a new theory of muscle contraction, termed the electrostatic linear motor model. The model consists of parallel plate capacitors that represent the myosin filament, a slider that represents the actin filament and a battery that represents a metabolic energy supply. Based on this model we derived the theoretical formula for the force generated by the electrostatic linear actuator. Using this formula, we designed and manufactured a unit actuator that has a single capacitor. It generated a force of 6.64 mN at 200 V. To increase the output force generated in the unit area of the actuator, we integrated twenty small unit actuators. The integrated actuator generated 42.3 mN at 200 V. Using these results, we designed a hollow fiber type linear actuator that was 30 cm long. It was expected to generate a pressure of 5 kglcm
2 with a stroke of 5 cm.
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—Improvement of signal transmission characteristics—
T. NOMURA, T. YASAKI, K. KOSLIIJI, E. SHU, T. UTSUNOMIYA, S. NLWA, H. ...
1994 Volume 23 Issue 1 Pages
41-46
Published: February 15, 1994
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This paper describes the performance of an improved transcutaneous optical coupler system. In this newly-designed system, an infrared LED and a set of phototransisters are placed face to face with the skin between them. Informations from a simulated artificial heart system are converted into an optical signal by the LED, transmitted through the skin, and detected by the phototransistors that are arranged in the shape of a circle. The informations are transmitted in the form of a digital signal in the infrared region because, in this way, power is effectively saved and high reliability in view of electromagnetic compatibility can be assured. With several phototran-sistors arranged in a set, and with a wave-shaping circuit added on the receiving side, the new system can allow for greater misalignment of LED and phototransistors that may possibly be caused by the movement of the patient. For a misalignment of 12mm, a signal transmission rate of 19200bps was attained with the new system, which is 8 times greater than what is possible with the conventional system. Attainment of this signal transmission rate was also confirmed by an in vivo experiment carried out with a grown goat.
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A. YAMAGUCHI, H. IDE, T. INO, H. ADACHI, A. MIZUHARA, K. KAWAHITO, S. ...
1994 Volume 23 Issue 1 Pages
47-51
Published: February 15, 1994
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A pulsatile left ventricular assist catheter(transaortic valve from left ventricle to lemoral artery)consisting of bypass tube(90cm in length and 15 Fr in inner diameter)and an accompanying intraaortic balloon as a single apparatus(Integrated cardioassist catheter; ICAC)has been developed. We have experienced first clinical application of the ICAC as a treatment for cardiogenic shock. When a 61 year old man with a myocardial infrction was admitted, the ECG revealed ventricular flbrillation. After the institution of a 3L/min. of PCPS flow support and IABP, coronary angiography and PTCA were perlormed. Because urine production decreased gradually and left ventricular function detected by TEE was depressed, the ICAC took the place of the PCPS. It took 30min. to change the cannulations, thereafer the left ventricular bypass was adjusted to 1.8L/min, with counterpulsation with the aid of a centrifugal pump and IABP console. After the application of ICAC, the urine production increased and left ventricular ejection fraction rose, however, the patient became unconscious and died six days alter admission due to cerebral infarction and hemorrhage. This clinical experience suggested that the ICAC enabled quickly institution of left heart bypass and was beneficial to left heart support.
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T. TAKAHAMA, F. KANAI, K. ONISHI, Y. NARUSE, Y. KANEKO, A. FURUSE, T. ...
1994 Volume 23 Issue 1 Pages
52-55
Published: February 15, 1994
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The present study was carried out to clarify better anticoagulation treatment during left ventricular assisting. Following results were obtained from the experimental circulation using adult dogs. In heparin group and argatroban group, prothrombin time prolonged during 24 hours, and in urokinase group, the level of fibrinogen decreased remarkably in the course of time. In nafamostat mesilate group, the level of fibrinogen and α2-plasmin inhibitor showed no significant change during the 24 hours, while in thromboxane A
2 synthetase inhibitor group, α2-plasmin inhibitor decreased sinificantly The combination of nafamostat mesilate and prostacyclin analogue, and nafamostat mesilate and thromboxane A
2 synthetase inhibitor are considered to be better anticoagulation therapy for left ventricualr assisting at the present time, because in both groups, the level of coagulation activity and fibrinolytic activity maintained within allowable range.
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H ANAI, T NAKATANI, E SASAKI, Y TAENAKA, H AKAGI, T MASUZAWA, Y BABA, ...
1994 Volume 23 Issue 1 Pages
56-59
Published: February 15, 1994
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Continuous monitoring method of pump performance by measuring electrical impedance in a blood chamber was applied to the trigger system of full-fill to full-empty(F/E) drive control. An automatic trigger level adjustment method(ATAM) for settlement of a trigger level to change a phase from ejecting to filling was developed to maintain a definite stroke volume against changes of afterload or driving pressure. ATAM was an automatic searching algorism that can identfy the volume change of last ejection by impedance method and settle next trigger level to maintain a destination stroke volume. In a mock circuit and animal experiments, ATAM functioned satisfactorily to follow the changes of afterload and driving pressure and maintained definite stroke volume. In conclusion, this method was practical and useful in regulation of F/E driving.
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—MINIMIZATION OF ARTERIAL AND VENUOS BLOOD MIXTURE IN CONTINUOUS FLOW PUMP—
T. ISOYAMA, K. IMACHI, T. CHINZEI, Y. ABE, K. MABUCHI, T. YONEZAWA, K. ...
1994 Volume 23 Issue 1 Pages
60-64
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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To develop a totally implantable artificial heart, a new mechanism of pulsatile total artificial heart, Flow Transformed Pulsatile Total Artificial Heart (FTPTAH), was proposed. It could perfuse the pulmonary and systemic circulatory systems by pulsatile flow using only one continuous flow pump. In a mock circulation, the latest model using a centrifugal pump could produce alternatively 7.81/min of outputinto the pulmonary and systemic circulatory systems. However, the arterial and venous blood mixture in the pump was pointed out. The mixture rate was 30.6% in original Sarns
† impeller. In this study, the influence of the impeller configuration and types of pump on blood mixture was examined. Several types of impellers and a mixed flow pump were designed. The blood mixture decreased to 20.7% in a centrifugal pump, and to 16.9% in the mixed flow pump.
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S. KOIDE, M. YOSHIZAWA, K. ABE, H. TAKEDA, T. YAMBE, S. NITTA, Y. ABE, ...
1994 Volume 23 Issue 1 Pages
65-70
Published: February 15, 1994
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In order to evaluate control characteristics of the circulatory system, frequency and cross correlation analyses of several parame-ters, i.e., heart rate(
HR), aortic pressure(
AOP) and peripheral vascular resistance(
R), of circulatory systems driven by natural heart and by total artificial heart(TAH) have been carried out. As the result of these analyses, Mayer wave fluctuation from the circulatory system driven by TAH without heart rate variability has been observed. This suggests that the fluctuation may have its source in the
AOP-
R loop. The effect of
AOP-
HR loop on suppression of mutual variabilty between
AOP and
R has been also clarified through comparison between two groups of data with TAH and without TAH.
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H. AKIHO, S. NITTA, T. YAMBE, S. NAGANUMA, Y. KAKINUMA, K. IZUTSU, S. ...
1994 Volume 23 Issue 1 Pages
71-75
Published: February 15, 1994
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To determine optimal driving modes of left ventricular assist device (LVAD) for the natural heart, acute experiments were performed in 8 adult goats. LVAD bypass flow was maintained within same value during the use of co-pulsation mode and conterpulsation mode by our adaptive control system. Total peripheral vascular resistance and natural heart output during each driving mode were evaluated. Total peripheral resistances were not significantly changed during each driving mode though natural heart output increased during the use of counterpulsation mode compared with co-pulsation mode. These results suggested that afterload of the natural heart was decreased during the use of counterpulsation mode and counterpulsation mode was desirable for the natural heart unloading.
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—Evaluation of the right ventricular pressure-volume relationship by the conductance catheter technique—.
C PARK, M KITANO, K NISHIMURA, Y OKAMOTO, T. BAN
1994 Volume 23 Issue 1 Pages
76-81
Published: February 15, 1994
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The purpose of this study is to assess the right ventricular(RV) performance during left heart bypass (LHB). To evaluate RV performance, RV maximal elastance (RVEmax) was assessed by the right ventricular pressure-volume relationship measured by conductance catheter. RVEmax was measured during varying degrees of LHB (assistance ratio 0 to 100% of pulmonary arterial flow). The LHB resulted in parallel shifts of RVEmax in normal hearts, but the full LHB decreased RVEmax in failing hearts which were produced by normothermic aortic clamping for 20 minutes. (3.95±0.93(mmHg/ml) vs. 3.00±1.36 (mmHg/ml), p<0.05). In the failing heart, RVEmax was in inverse correlation with the change of right ventricular end-diastolicvolurne more clearly rather than the change of the assist flow of LHB.
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A SAITO, T NAKAYAMA, H MORO, H OHZEKI, J HAYASHI, H MIYAMURA, S EGUCHI
1994 Volume 23 Issue 1 Pages
82-86
Published: February 15, 1994
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Hydrophilic-hydrophobic microphase separated structure (microdomain) had been thought to suppress platelet adhesion and activation. We applied a new antithrombogenic material (Microdomain-Fμ), which was a microdomain polymer mixed with a lubricating hydrophilic polymer, to a circuit tubing designed for circulatory assist. Twenty-four hours of venoarterial bypass without systemic heparinization was performed in 4 pigs. Hematologic markers was not fluctuated until 6 hours after the initiation of the bypass. Scanning electron micrographs of the explanted tubes after 24 hours of bypass revealed platelet aggregation on the surfaces of the inflow portion and the pump tubing, although there were few findings of platelet activation in the outflow portion. Our study indicates that this new polymer has an ability to suppress adhesion and activation of platelets in the circuit without turbulence.
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Noriyoshi KUTSUKATA
1994 Volume 23 Issue 1 Pages
87-91
Published: February 15, 1994
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We developed a clinical instrument to calculate the supply/demand ratio (SDR) which was advocated by Buckberg, and was defined as the ratio of the diastolic pressure time index (DPTI) divided by the tension time index (TTI). We tested the instrument on 20 consecutive patients who underwent open heart surgery with cardiopulmonary bypass. The SDR was measured at 30 mins to 18 hours after aortic declamping and compared to the coronary sinus oxygen consumption (CSO
2) using an optic fiber catheter (Opticath, Abbott) placed in the coronary sinus, the cardiac index (CI) and the stroke volume index (SVI) using a Swan-Ganz catheter, and several other parameters (level of lactate, pyruvate and creatinin phos-phkinase in coronary sinus blood) of myocardial oxygen metabolism. SDR correlated with CSO
2 (Y=30.9X+20.8, R=0.72, N=87, p=0.001) and SVI (Y=14.8X+18.2, R=0.73, N=42, p=0.05). However, CI and the other parameters had no correlation with SDR. We concluded that measurement of the SDR is useful for the evaluation of hemodynamics after a cardiac operation, and for prediction of the myocardial oxygen extraction.
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T. NAKAZAWA, T. HASEGAWA, M. SHIONO, Y. ORIME, T. INOUE, H. MIMURO, K. ...
1994 Volume 23 Issue 1 Pages
92-96
Published: February 15, 1994
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We designed a new device that incorporated a VAD out let with a membrane oxygena-tor, and examined the result. In the mock circulstion study, a sufficient inlet flow from the membrane oxygenator for oxygenation and removal of carbon carbon carbon dioxide was obtained Sufficient flow and pressure to maintain systemic circulation were also obtained. In the hypoventilation and heart failure models' study, with this device, hemodynamics were improved and recovered from heart failure. This device was also able to maintain systemic circulation. And the deta of blood gas analysis was also improved. In the subacute study, during 76 hours with this device, there were no hemolysis, thrombosis. These results suggest that this new assisted-circulation system is possibly a superior circulation assist method which has circulatory assist effects and respiratory assistanec capabilities. Moreover, we suspect that these findings can be put to use for PCPS and in clinical cases that include heart failure associated with respiratory failure.
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T. NAKATANI, H. ANAI, K. ARAKI, Y. WAKISAKA, Y. TAENAKA, H. AKAGI, T. ...
1994 Volume 23 Issue 1 Pages
97-101
Published: February 15, 1994
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Right ventricular (RV) assistance is essential in severe RV failure to maintain total circulation. There is, however, no easy wayto introduce RV assist. For left ventricular (LV) assist, an intraarterial axial flow pump (Hemopump) has been developed and used clinically. In this study, the feasibility of intravenous use of an axial flow pump was examined with modified Hemopump for intravenous insertion. The modified Hemopump designed for RV assist was tested in an adult goat by retrograde introduction from the pulmonary artery. Positioning of the cannula was easy and the system showed good RV assistance under induced pulmonary hypertension or induced biventricular failure. In vitro testing of a modified Hemopump for antegrade intravenous insertion indicated that maximum flow at a pressure differential of 40mmHg is 4.0l/m. Insertion from peripheral vein was performed uneventfully and good RV assistance was achieved. These data suggest that an axial flow pump introduced via an antegrade intravenous approach may provide sufficient right heart assist.
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K. KAWAHITO, T. INO, H. ADACHI, H. IDE, A. MIZUHARA, A. YAMAGUCHI, S. ...
1994 Volume 23 Issue 1 Pages
102-106
Published: February 15, 1994
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We applied partial cardiopulmonary bypass(CPB) with a new antithrombotic system for the circulatory support system to six patients with descending thoracic aortic operation. This system consisted of a Bio-Medicus centrifugal pump, Carmeda membrane oxygenator, and poiyvinylchloride tubing materials which are all coated with heparinized polymer except for cannulas. Cannulas are coated new antithrombogenic coating material Fluorine-acryl-styrene-urethane-silicone copolymer. Low dose of heparin(50U/kg) were administered and activated coagulation time was maintained 200 seconds. Four patients were uneventful in their postoperative course, two patients died of intestinal necrosis, which was not related with this technique. There were not bleeding accidents nor evidences of thromboembolism, furthermore, postoperative examination revealed no thrombus formation in the devices. In conclusion, partial CPB with a new antithrombotic system may be beneficial in descending aortic operation from the view points of avoidance of the risk of hemorrhage, and maintenance of adequate circulatory and respiratory support
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K. IMANISHI, K. IMACHI, T. ISOYAMA, Y. ABE, T. CHINZEI, K. MABUCHI, I. ...
1994 Volume 23 Issue 1 Pages
107-113
Published: February 15, 1994
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To make a more effective assist device we developed the third model of assist device (MAD Type-3). The system is composed of a blood pump and a cannula. The blood pump had a single port sac type blood pump with a stroke volume of 60ml. The cannula had a 5.6mm internal diameter and was 40cm long. A new inflow and an outflow valve have been designed. The inflow valve had a shape of bullet. The outflow valve had a shape of skirt. So the inflow and out-flow valve were called the Truncated Conical Jellyfish Valve and the Skirt Valve respectively.
In the mock circulation study, a maximum flow of 2.05l/min was obtained. The in vivo experi-ments were performed. with MAD assistance the marked systolic unloading and diastolic augmen-tation were observed. The increase of the coronary flow and aortic flow were observed. In conclusion, this third model of assist device (MAD Type-3) was thought to be put into clinical use in the near future.
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Kenji OKADA, Yoshikado SASAKO, Takeshi NAKATANI, Masanobu WATARI, Moto ...
1994 Volume 23 Issue 1 Pages
114-118
Published: February 15, 1994
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A 59 year-old man with DeBakey type I dissecting aneurysm had underwent Bentall operation and graft replacement of the aortic arch using “elephant trunk” technique, and developed cardiogenic shock following the operation. Femoro-Femoral Veno-Arterial bypass (VAB) combined with intraaortic balloon (IAB) pumping was utilized effectively. However, the left brachial arterial pressure fell down to 20mmHg suddenly, while the femoral arterial pressure elevated to 200mmHg. To clarify this phenomenon, we studied the hemodynamic effect of IABP after “elephant trunk” technique by using mock circulation. When the IAB was extruded 10cm from the graft, upper-lower blood flow ratio (Q
u/Q
1) was reduced to 0.18 from 1.0 on IABP, which revealed the preferential blood flow to the lower half of the body. Tn “elephant trunk” technique using a graft with small diameter, collapse of the graft was observed at IAB inflation, and the pump function toward the non-fixed terminus was observed. These findings indicated that IABP should not be used as a circulatory assist for postcardiotomy shock after “elephant trunk” technique.
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T MURAKAMI, K HISAMOCHI, T KOOMOTO, M TAKAGAKI, S NAWA, N SHIMIZU, S K ...
1994 Volume 23 Issue 1 Pages
119-123
Published: February 15, 1994
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Over the last 5 years, 15 patients received VADs and 5 received CPS in postoperative cardiogenic shock. The duration of VAD support ranged from 6 hours to 9 days (mean, 3.9 days). The duration of CPS ranged from 4 hours to 8 days (mean, 2.8 days). Thirteen VAD patients were weaned and S survived. Bleeding occurred in 5 patients, renal failure in 4, infection in 3, cardiac failure in 4, cerebral infarction in 1, perioperative MI in 1, arrhythmia in 1 and ileus in 1. Four CPS patients were weaned and 3 survived. Bleeding occurred in 3 patients, renal failure in 2. CNS injury in 2, and cardiopulmonary failure in 1. The 8 VAD survivors have been followed for 2 to 56 months. Five were in NYHA class I, 2 were in class II and one was in class III. The 3 CPS survivors have been followed for 6 to IS months. Two were in class I and one was in class III. The VADs and CPS were both effective in supporting circulatory failure, but serious complications were observed more frequently in CPS patients.
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K. UCHIYAMA, N. FUJISAWA, Y. SHIMAZAKI, M. RANAWAKE, T. FUJIMOTO, M. U ...
1994 Volume 23 Issue 1 Pages
124-129
Published: February 15, 1994
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We have developed an automated “Arm Robot” Fabrication System (ARFS) to make the leaflets of a polyurethane (PU) valve for use in ventricular assist devices (FAD). Preliminary testing using the ARFS resulted in a 27% success rate of the valves fabricated, as compared to 50% for the hand made valves. To gain a better understanding of the deviations in thickness of the leaflet, we measured it at a 135 different points using a Miniature moire measuring system. Of the ARFS made valves, the max. deviation between the three leaflets was at 25um. and 47um. for the hand made valves, while the leaflet itself became thicker towards the base. This result indicated a much more even thickness distribution in the ARFS made valves. From valve fatigue testing and using the FEM (finite element method) it was evident a thickness of approximately 300um. at the base of the leaflet is necessary to achieve long term durability. Although problems remain the ARFS, as the thickness of the valve is better controlled using this system, it is reasonable to assume parameters of valve performance including, durability, leakage & pressure drop are also better controlled.
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G. OHTSUKA, M. KITAMURA, H. TOKUNAGA, R. IDE, M. MIYAGISHIMA, H. OZAWA ...
1994 Volume 23 Issue 1 Pages
130-132
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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a comparative study with dacron sewing cuff-From 1980, the St. Jude Medical (SJM) valve prostheses were implanted in mitral position in 708 adult patients. Before March in 1991, the prostheses with dacron sewing cuff were used in 614 patients. There were 11 cases required reoperation The causes of reoperation in 8 of them were hemolysis and perivalvular leakage. 7 of these 8 cases were suffered prior operation in mitral position. Since March in 1991, the SJM prostheses with teflon sewing cuff were implanted in 94 patients There was no case required reoperation. The postoperative serum LDH level were compaired betueen the cases using dacron cuff and the cases using teflon cuff. There was no significant differencee between them o There might be the better tendency to avoid hemoiysis and perivalvular leakage in the SJM prosthesis with teflon sewing cuff.
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T OKOSHI, Y NOISHIKI, Y TOMIZAWA, Y EGOH, H KOYANAGI
1994 Volume 23 Issue 1 Pages
133-136
Published: February 15, 1994
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Nonthrombogenicity of a polyepoxy compound (PC)-crosslinked heart valve (PC valve) was evaluated in the right and left heart systems. Aortic valves harvested from mongrel dogs were crosslinked with PC, and fabric vascular prothseses were ansatomosed proximal and distal to the valve (PC-valved conduit). Another type of conduit with a glutaraldehyde-crosslinked heart valve (GA valve) was fabricated as a control (GA-valved conduit). Both types of conduits were implanted as a right ventricle-pulmonary artery bypass graft and the main pulmonary artery was ligated (right heart system model)(PC valve: 8 dogs, GA valve: 8 dogs). Both types of conduits were also placed as a left ventricle-descending aorta bypass graft (apico-aortic bypass graft) and the descending aorta was ligated at its proximal portion (left heart system model)(PC valve: 2 dogs, GA valve: 1 dog). The valves implanted in the right and left heart systems were retrieved 14 to 37 days and 7 to 20 days after implantation respectively. Macroscopical evaluation of each cusp of the valves revealed that PC valves had significantly less thrombus formation than GA valves in the right heart system (p<O.05) and that PC valves showed a tendency to be less thrombogenic than GA valves in the left heart system.
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Jun-ichi HAYASHI, Hirofumi OKAZAKI, Satoshi NAKAZAWA, Yasuo FUJITA, Hi ...
1994 Volume 23 Issue 1 Pages
137-141
Published: February 15, 1994
Released on J-STAGE: December 02, 2011
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Late postoperative outcome of aortic prosthetic valves, which was implanted between March 1976 and March 1993, were reviewed. A linealized rate of thromboembolic event was 0.61, 0.60, 0.54, 0.42%/pt·Y in patients with Björk-Shiley spherical disc, Lillehei-Kaster, Omniscience, St.Jude Medical prosthetic valve, respectively. Thrombosed valve occurred frequently in Omnisci-ence valve (1.62%/pt·Y) . Among those prosthetic models, there were no significant differences in linealized rate of anticoagulation-related hemorrhage, prosthetic valve endocarditis and prosthesis-re-lated death including sudden death. Actuarial survival rate at 10 years postoperatively were 94.2% in St.Jude Medical, 88.3% in Omniscience, 76.7% in Björk-Shiley and 66.7% in Lillehei-Kaster prosthetic valve. In patients with Duromedics valve there was no postoperative complications, and the survival rate was 94.7% at 8 years postoperatively. In patients with St.Jude Medical (Teflon sewing cuff) and Björk-Shiley monostrut prosthesis, no signs of intravascualr hemolysis were seen, and the level of lac-tate dehydrogenase were allowable. Carbomedics valve was successfully implanted in 8 patients with narrow aortic ring, subvalvular patch repair and annuloaortic ectasia. ‹Conclusion› (1) In the pre-sent series, bileaflet valves were demonstrated to be superior to tilting disc valves in antithrom-bogenicity. (2) In selective cases, Björk-Shiley monostrut valve, St.Jude Medical with Teflon cuff and Carbomedics were considered to be useful alternative.
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T. OTA, K. IWAHASHI, H. MATSUDA, K. ATAKA, M. OKADA
1994 Volume 23 Issue 1 Pages
142-146
Published: February 15, 1994
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Degree of left ventricular (LV) afterload reduction after implantation of SJM19 was examined. Patients were divided into two groups; groups S (BSA<1.45, n=10) and L (≥1.45, n=10). Maximal pressure gradients (maxPG) measured with Dopplerecho in group S/L were 30/25 mmHg (p=NS). The maxPG was also measured during dobutamine administration, then significant correlation was found cardiac output (CO) and maxPG. The 40 mmHg of PG was estimated when CO was approximately 81/min. Reduction rates in group S/L were 16/15% in LV wail thickness, 30/26% in LV mass and 27/30% in LV cross sectional area (p=NS in each). In conclusion, implantation of SJMI9 obtains afterload reduction in patients with BSA<1.6. However, limited use is recommended because the increase of maxPG corresponding to the increase of CO cannot be ignored.
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Study of Mitral and Aortic position
S. HOSHINO, Y. IMAI, K. ISHIHARA, K. SAWATARI, S. NAKATA, M. TERADA, H ...
1994 Volume 23 Issue 1 Pages
147-150
Published: February 15, 1994
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From January, 1979 through December, 1992, 77 children less than 15 years old old who underwent MVR (41 cases) or AVR (36 cases, including 29 Konno procedures), with SJM prostheses were discharged from our institute. Cumulative duration of follow up was 303.8 patient-years for MVR and 184.3 p-ys for AVR. There were three late deaths in the MVR group and two late deaths in the AVR group. Actuarial survival rates was 91.7±4.7% for MVR at 14 years and 94.4±3.9% for AVR at 12 years (N. S.). I n the MVR group, there were three cases of nonstructural dysfunction (0.99%/ p-y), one episode (0.33%/p-y) of thromboembolism, thrombosed valve, brain bleeding and prosthetic valve endocarditis (PVE) respectively. On the other hand, there was only one thromboembolism (0.54%/ p-y) in the AVR group. The results of valve replacement using SJM prostheses in children over a 12-year-period were satisfactory. Therefore, we continue to choose SJM mechanical valve as the first choice in children who require cardiac valve replacement.
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Y. FUJITA, S. TSUCHIDA, J. HAYASHI, S. EGUCHI, J. HONI, Y. SAITO
1994 Volume 23 Issue 1 Pages
151-154
Published: February 15, 1994
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We studied the closing sound of SJM prosthetic heart valve(SJM) by the power-frequency-time analysis, using the fast Fourier transform; the method of Wigner-Ville. The peak of distribution of power-frequencytime surface was around 1.3 to 1.5KHz, and its maximal value was up to 5.0 KHz. As the frequency of the sound spectrum became higher, the power became weaker proportionally . By the pseudo-thrombus attachment to the SJM ring, decrease in the power was noted especially in the range of 1.5 to 3.0 KHz. When the size of the pseudo-thrombus was gotten to be bigger, decrease in the power in the range of 1.5 to 3.0 KHz was also noted. Furthermore, the appearance-time of the sound spectrum got shorter. When it was the maximal size of pseudo-thrombus, finally, the distribution of the continuous frequency peaked at 1.0 KHz was only noted. In this study, by analysis of the power-frequency-time analysis of the closing sound of SJM, the decrease in the power as well as shortening o f the appearance-time of the spectrum were noted in the case of the pseudo-thrombus attached on SJM. It was soncluded that the powerfrequency-time analysis of closing sound of SJM was useful for the early and accurate diagnosis for its malfunction.
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Y. OHTA, Y. TADA, T. DOHI, T. HORIUCHI
1994 Volume 23 Issue 1 Pages
155-159
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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we devekoped a computer-controlled hydraulic mock circulator to investigate mechanism of motions of mechanical prosthetic heart valves and studied their in vitro motions under the flow condition controlled with high accuracy. The Omnicarbon valve, the Björk-Shiley valve and the Medtronic-Hall valve were tested at mitral position. These valves were driven under single-or double-peak flow condition and were photographed by a high speed CCD camera. Flowrate, BPM and S/D ratio were set as 4.0 L/min, 70 and 0.3, respectively. By analyzing the images of the valves we found: 1) there was no significant difference in motion among the three valves tested. 2) an unstable motion was observed as the decrease of inflow rate. 3) a temporary closure of the disc occurred at the least inflow rate between two inflow peaks.
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K. NAEMURA, K. HASHIMOTO, K. UCHIYAMA, Y. KATO, T. FUJIMOTO, M. UMEZU
1994 Volume 23 Issue 1 Pages
160-163
Published: February 15, 1994
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In order to clarify the effect of atrial contraction on the hydrodynamics at mitral valve, a new-type mock circulatory system has been developed. In this system, an artificial atrium can be slightly collapsed prior to the contraction of the ventricle. After the modification of the software of the pneumatically-operated heart driver, both atrium and ventricle could be synchronously driven under different drive timings for the two chambers. An extraordinarily high pressure peak, which is known as the waterhammer phenomenon, is generally measured in the vicinity of the valve. However, the waterhammer level could be reduced by 40% when the atrium was actively driven for 50msec prior to the contraction of the ventricle. The results through this experiment suggested that the drive timing for two chambers indicated a great factor on the valve closure, and they also exhibited that the prosthetic valve performance were able to be evaluated by using this newly-developed mock circulatory system under physiologic conditions.
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T ISOMURA, K HISATOMI, A HIRANO, T STOH, A OOHASHI, E TAYAMA, K TANAKA ...
1994 Volume 23 Issue 1 Pages
164-166
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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Between 1980 and 1992, 583 patients received mitral valve replacement with the St. Jude Medical prosthesis and their early and late results were studied. The prosthesis was placed in anatomical position in 143 patients until 1983, and then the prosthesis was implanted in anti-anatomical position since 1984. Postoperative anti-coagulant therapy was initiated with both dipyridamole and warfarin potassium. The total follow-up was 3176 patient-years. Early deaths occurred in 18 patients. the cerebral embolic or bleeding complications occurred in 21 patients (0.66/100 patient-years) and late cardiac events were seen in 65 patients (1.98/100 patient-years). Late death occurred in 42 patients (1.08/100 patient-years). Ninety % of the patients were followed up, and the survival rate at 5 or 10 years after operation was 91.2% or 87.8%, respectively. Postoperative New York Heart Association functional class was I or II in 89.1%. The clinical results after MVR with the St. Jude Medical prosthesis showed excellent durability and patients showed good improvement of the symptoms.
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T TANAKA, S INOUE, N KIMURA, T ABE, S KOMATSU
1994 Volume 23 Issue 1 Pages
167-170
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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Between February 1985 and April 1993, 79 patients who had isolated MVR with three different kinds of bileaflet valves (St Jude Medical: SJM in 30, Duromedics: DM in 30, CarboMedics: CM in 19) were hemodynamically analyzed in this study. All patients had postoperative cardiac catheterization which was performed at rest and on exercise about 2 months after surgery. There were no significant differences between in three kinds of valves with hemodynamic data, valve function and hemolysis. Three bileaflet valves of SJM, DM and CM have had excellent valve function in mitral position at rest and on exercise.
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M KUWABARA, T ONITSUKA, K NAKAMURA, K FUKUMOTO, Y KOGA
1994 Volume 23 Issue 1 Pages
171-173
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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We evaluated long-term survival analysisand quality of life over 10 years after heart valve replacement with a St. Jude Medical prosthetic valve in 44 patients (7 underwent aortic valve replacement, 31 underwent mitral valve replacement, 5 underwent double velve replacement, and 1 underwent Bentall operation). Two died of valve related factor. Actuarial survival rate of total, AVR and MVR were 87.3%. 83% and 93.1%. respectively. Thromboembolism free rate, re-operation free rate, and prosthetic valve endocarditis free rate were 92.4%, 90.0%, 97.6%, respectively. Valve related event free rate was 89.7%. In conclusion, this study demonstrated that the SJM valve showed a low incidence of event over 10 years after operation. These results endorse our choice of the SJM valve.
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M. WATANABE, H. IWAYA, T. IGARI, K. HAGIWARA, H. SATOKAWA, H. MIDORIKA ...
1994 Volume 23 Issue 1 Pages
174-179
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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The valvular and cardiac function undergoing mitral valve replacement with Omniscience (OS) and Medtronic-Hall (MH) valve have been assesed retrospectively and compared using transesophageal echocardiography. No statistically significant differences were obtained regarding peak pressure gradient, peak velocity, obligatory regurgitation and cardiac function. But, pressure half time of the OS group was 100.5msec and that of the MH group was 82.8msec with a statistically signicant difference. Opening angles of the prosthesis were larger in the MH group compared with those in OS group and reoperation was performed in 11 patients in the OS group.
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H SHINTANI, S NAKANO, Y SHIMAZAKI, K TANIGUCHI, V MIYAMOTO, H YASUDA, ...
1994 Volume 23 Issue 1 Pages
180-183
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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To evaluate the relation between asynchronous motion of the prosthetic valve and its function after implantation, prosthetic valve function and motion of each leaflet were investigated in 14 patients with CarboMedics (CM) mitral prosthetic valve replacement. There were no valve-related events during the 11.7-month follow-up period. No significant regurgitation and paravalvular leakage weredetected by color-Doppler echocardiograms. Time-related changes in LDH values after valve replacement were not related to asynchronous motion of the CM valve. Effective mitral valve area measured by pulse Doppler echo cardiograms were not significantly different from actual internal orifice. Open angle of each leaflet was almost identical with the designed open angle 78°. Asynchronous motion of the leaflets was observed in 8 of 14 patients. In 2 of the 8 patients, not only synchronous motion but asynchronous closure of the leaflets were also observed. In all 8 patients, asynchronous motion of the leaf-lets was accompanied with atrial arrhythmia. These findings suggest that there would be no relation between asynchronousmotion and its function, but longterm follow-up should be necessary in patients with CM mitral valve replacement accom-panied with atrial arrhythmia.
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M. KIMURA, T. SUGIURA, T. KIMURA, Y. HARADA
1994 Volume 23 Issue 1 Pages
184-187
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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A temporary bipolar epicardial pacing device which is constructed by flexible carbon fiber and fibrin glue was proposed. This device can be attached to the surface of the cardiac muscle easily. Developed pacing leads were applied to 3 mongrel dogs. The electrodes were attached to the animals' right atrium. For one week, the pacing threshold voltage and the inter electrode impedance were measured. In all cases, the pacing threshold were less than 5 volts and the inter electrode impedance were between 300 ohm and 700 ohm. These values were allowable for epicardial pacing. After one week from the implantation, the leads could be pulled out safely without any bleeding. Proposed pacing lead is promising as a epicardial pacing device.
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Keiichiro KATSUMOTO, Tatsuru NIIBORI
1994 Volume 23 Issue 1 Pages
188-192
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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Threshold elevation was observed in the pacing electrode within the seven to ten days after implantation. We studied whether the threshold elevation would be mitigated when steroid was made eluting from the surface of the glassy carbon electrode.At first, we dipped the electrode into the mixture of dimethyl silicon oil and dexamethasone sodium phosphate (DSP) powder, just before electrode insertion. This method was not so effective. Secondly, we made four drilling holes of 300 μm in diameter in the surface of the glassy carbon electrode, and filled silicon gel in them mixed with DSP. With this method, threshold elevation was effectively suppressed at the 7th post operative day compared with the steroid non-eluting control electrode of the same design, either in the atrial or ventricular pacing. Energy threshold was successfully lower in the steroid eluting glassy carbon electrode (DS58V) when compared with commercially available Capsure 4003 electrode. However, at 10 months, there was no difference in threshold between the steroid eluting and non-eluting DS-58V electrode.
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Y YAMAMOTO
1994 Volume 23 Issue 1 Pages
193-198
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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Sinus rate and activity sensor rate during consecutive daily activities were recorded by the internal rate profile function of Intermedics DASH. Sensor rate profiles with different rate response parameters were redrawn by the redraw function of DASH without repeating exercise. As the result, sensor rate was under-responsive with lower-lebel exercise when rate response parameters were set for higher-lebel exercise, and was over-responsive with higher-lebel exercise when parameters were set for lower-lebel exercise. Time delay of rate response was noted with higher-lebel exercise following lower-lebel exercise in most of subjects. These phenomena were found both in DASH and Medtronic LEGENDII, suggesting limitation of activity sensor and rate response algorism. The rate profile and redraw functions were useful for evaluation of the rate responsive pacemakers.
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T. TAKAGI, S. MIZUSHINA, T. SUGIURA, M. KIMURA, T. KIMURA, Y. HARADA
1994 Volume 23 Issue 1 Pages
199-202
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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We have reported the fuzzy-rates control by 2 parameters (minute ventilation, MV and oxygen saturation, OS) in rate adaptive cardiac pacing. Although the overall agreement between fuzzy-rates and target rates was satisfactory, the fuzzy-rates before and after exercise were almost at the same level (fuzzy-rates immediately decreased to the restinglevel before exercise, as far as MV and OS are used as the rate-controlling parameters, it is impossible to keep the fuzzy-rates higher after exercise because MV and OS are almost the same level before and after exercise. To improve this, we propose to add one more parameter which has generally the different values before and after exercise. We developed the automatic generation method of control rules for the 3 parameters pacing system and demonstrated its feasibility using MV, OS, and temperature, as the 3rd parameter. The preliminary simulation results were satisfactory. Automatic tuning methods of membershi functions and controlrules are under study.
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T. ISHIKAWA, K. KIMURA, T. EBINA, T. USUI, M. KASHIWAGI, M. ISHII
1994 Volume 23 Issue 1 Pages
203-206
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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Although the overdrive suppression test (ODST) is important in detecting sick sinus syndrome (SSS), its sensitivity is still not satisfactory. We evaluated the effect of intravenous injection of disopyramide phosphate (DP) in ODST. The subjects were 30 SSS patients (65.7±10.0 years old). If sinus node recovery time (SNRT) was<2000ms or the corrected SNRT (CSNRT) was<1000ms, ODST was repeated after DP iv (2mg/kg, ≤100mg in total). Eleven normal subjects (59.3±9.0 years old) were also studied. Although the conventional ODST was negative in 13 of the 30 SSS patients (43%). SNRT was prolonged from 1510±300 to 3400±1160ms (p<0.01), CF from 510±190ms to 2470±1470ms(p<0.01) after DP iv. in these patients. Thus, SNRT and CRT was positive in 27 of the 30 SSS patients (90%) after DP iv. SNRT and GMT were rather shortened in the normal subjects during ODST after DP iv. (p<0.01). The plasma concentration of DP examined in 9 patients was 4.1±1.0mcg/ml. No serious side effect occurred. ODST employing DP iv. is safe and seems to be highly effective in diagnosing SSS.
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T MASEKI, H ARIKI, Y TAKAGI, K YASUURA, T ABE, M MURASE, T ISHIHARA
1994 Volume 23 Issue 1 Pages
207-211
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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Three hundred and eighty two transvenous polyurethane insulated atrial pacing leads were followed up and their survival probability was reviewed with special reference to lead failure. The survival probability (SP) was calculated with Kaplan-Meier method by models and compared with generalized Wilcoxon test. The SP of model 69910 was 37.7% at 12.5 years after implantation and the lowest significantly (p<0.01) among all models. Careful observation is necessary on this leads. The SP of models 6990U, 4502 and 4512 was 93.3% at 14 yrs, 91.4% at 11 yrs and 86.7% at 9 years respectively. The SP of models 4504 and 4524 was 100% to 4 and 2 years respectively. This increase of SP resulted from improved lead technology. The SP of all polyurethane atrial leads was 97.4%, 84.7% and 76.6% at 5, 10 and 14 years, respectively. The mean survival of all atrial leads was 12.8 years. These results showed relatively poor survival probability of polyurethane insulated atrial leads after 10 years post-implant.
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H ISEKI, H KATOUGI, Y SOMA, R YOZU, T UEDA, S TAGUCHI, H SHIMIZU, S KA ...
1994 Volume 23 Issue 1 Pages
212-215
Published: February 15, 1994
Released on J-STAGE: October 07, 2011
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In our hospital of Keio University Hospital, we experienced 346 cases of pacemaker implantation including 24 cases in infants and small children for the last twenty years. In the infant case, we must take care of where to implant a generator and which technique of lead placement because of the patient's small body, and the follow-up with the patient's growth. We examined several complications in an infant case, by comparing the long term results between infants and adults.We found the high incidence of the complications including five cases of wound infection and 4 cases of pacing failure due to exit block in children. The reason is that an epicardial lead is used and a generator is placed in the abdominal wall. we should use the technique for transvenous pacemaker implantation in infants and small children if possible.
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M NOMA, M SATOH, M ABE, T JIKUYA, N ATSUMI, Y TERADA, Y SAKAKIBARA, T ...
1994 Volume 23 Issue 1 Pages
216-220
Published: February 15, 1994
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From 1976 to 1992, 328 pacemakers were implanted or reimplanted in our clinic. Six patients were treated during the same period for pacemaker system infection. Three cases were treated with total pacemaker system removal and the other three were treated with partial removal. Treatment was successful in all cases.
In pacemaker infections, all foreign material must be removed to eradicate associated infectin. But total system removal is difficul when the lead is firmly fixed after long term. When tined tip is used, it is also difficult to remove the total system. In our clinic, treatment of pacemaker injections in done step by step as below. We try to remove total pacemaker system as a first approach. When it is not possible to pull the lead out, we treat them conservative after partial system removal as a second approach. And when we still can not control the infection after all, we remove total system under cardiopulmonary bypass.
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M. YAMADA, T. NARISAWA, M. AIBA, N. TANIO, H. TANAKA, M. FUNAMI, K. IN ...
1994 Volume 23 Issue 1 Pages
221-223
Published: February 15, 1994
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From January 1989 to December 1992, a total of nine patients were treated surgically for infections involving cardiac pacing system. Total removal of pacing system were done in five cases, removal of generator and part of lead in two cases, removal of only generator in two cases. All these three procedures involved generator pocket replacements. No further reaction of infection has been noted for at most 49 months after the surgical treatment. We concluded that optimal treatment is not always obtained by only total removal of all pacing system.
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H. SAKAI, M. NAKATA, S. MURATA, T. TAKEUCHI
1994 Volume 23 Issue 1 Pages
224-227
Published: February 15, 1994
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It is known that in long-term perfusion there is a decline in the gas transfer performance of a membrane oxygenator due to the plasma leakage and the absorption of plasma protein on the surface of microporous membrane. We experienced the same decline in the gas transfer performance and made a fundamental experiment with high freqency jet ventilator (HFJV) instead of gas blender and gas flow meter to prevent the “ Wet Lung”. The oxygenation in 200-400/min vibration with HFJV is significantly better than that without HFJV. Then we applied this HFJV clinically and even in the long-term perfusion (182hrs. ) the ABGA was excellent and we didn't need to exchange the membrane oxygenator. This is our only clinical experience and it is suggested that HFJV could prevent the “ Wet Lung” and the decline in the gas transfer performance even in the long-term perfusion.
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